Underwater Photogrammetry & 3DF Zephyr Webinar with FAQs

Recently we held a webinar that introduced how 3DF Zephyr workflow is used to create highly representative 3D photogrammetry models and 2D ortho mosaics of the underwater world. You can watch a recording of the webinar below.

We thought it would be helpful to collate a range of FAQ’s about Underwater Photogrammetry 3DF Zephyr on one page for our customers.

FAQ’s Underwater Photogrammetry & 3DF Zephyr

Is there a native Linux or Mac Version available or planned for 3DF Zephyr? And meanwhile, how stable/usable is the Linux + Wine workaround for 3DF Zephyr?

It is possible to run Zephyr under Wine, including CUDA, but requires tinkering and is not officially supported.

Will it calibrate with PTLens?

The strong recommendation is to never use 3rd party software to correct lens distortion. Given that, let the photogrammetry software sort it out.

The lens looks like AI AF Fisheye-Nikkor 16mm f/2.8D?

Correct – lens of choice for UW work is 16mm fisheye.

Does it correct for Rolling shutter?

We do not recommend using rolling shutter with moving capture. Instead, this technique can help negate or eliminate rolling shutter distortion.

Will 3dF Zephyr render with AMD graphics card?

Zephyr will run, but it only supports GPU acceleration on CUDA devices. AMD cards will run but the processing will remain in CPU.

Is it useful to calibrate the camera underwater specifically ?

No calibration required.

Does it have coded target recognition?

Yes, coded targets are available.

Can you build a DTM without real world georeferenced markers?

Yes, but the results will only be relative to the manually orientated model and chosen Z dir for the ortho.

Is there a control to set for fisheye?

No, calibraton step detects this.

How is 3DF Zephyr handling poor visibility and backscatter?

Good – tested with real world datasets from the English Channel.

Do you have any tips for taking pictures of structure with lower visibility?

Get close. Also, Use artificial lighting – strobes not video lights.

I’m an ROV pilot any recommendations for continued learning?

Yes! Additionally, our training course is approved by 3DF: https://accupixel.co.uk/courses/3df-zephyr-foundation-course/

In closing

Additionally, AccuPixel’s shop is now open for 3DFlow.

Furthermore, If you have any further questions – please do not hesitate to contact us – we would be happy to help.